Science Fiction
Dictionary
A B C D E F G H I J K L M N O P Q R S T U V W X Y Z
 |
Emdrive Electromagnetic Drive For Chinese Space Ships?
Tired of those conventional space drives that require some sort of reaction mass? Chinese researchers claim to have confirmed the basic principles behind the Emdrive - an electromagnetic drive concept that converts electrical energy into thrust using microwaves.
The Chinese are currently building a demonstration model to see if it works.
('Emdrive' Electromagnetic Space Drive)
Take a look at the explanation offered on Roger Shawyer's Emdrive website:
The principle of operation is based on the well-known phenomenon of radiation pressure. This relies on Newton’s Second Law where force is defined as the rate of change of momentum. Thus an electromagnetic (EM) wave, travelling at the speed of light has a certain momentum which it will transfer to a reflector, resulting in a tiny force.If the same EM wave is travelling at a fraction of the speed of light, the rate of change of momentum, and hence force, is reduced by that fraction. The propagation velocity of an EM wave, and the resulting force it exerts, can be varied depending on the geometry of a waveguide within which it travels. This was demonstrated by work carried out in the 1950’s. (CULLEN, A.L. ‘Absolute Power Measurements at Microwave Frequencies’ IEE Proceedings Vol 99 Part 1V 1952 P.100)
Thus if the EM wave travelling in a tapered waveguide is bounced between two reflectors, with a large velocity difference at the reflector surfaces, the force difference will give a resultant thrust to the waveguide linking the two reflectors. If the reflectors are separated by a multiple of half the effective wavelength of the EM wave, this thrust will be multiplied by the Q of the resulting resonant cavity.
The inevitable objection raised, is that the apparently closed system produced by this arrangement cannot result in an output force, but will merely produce strain within the waveguide walls. However, this ignores Einstein’s Special Law of Relativity in which separate frames of reference have to be applied at velocities approaching the speed of light. Thus the system of EM wave and waveguide can be regarded as an open system, with the EM wave and the waveguide having separate frames of reference.
The beauty of engineering is that you can actually build something to test it; we'll find out soon enough if Emdrives will power space craft.
In the meantime, you might want to compare the Emdrive explanation with other famous pseudo-scientific science-fictional space drives. See the entries for the spindizzy from James Blish's Cities in Flight and of course the elegant infinite improbability drive from Douglas Adam's Hitchhiker's Guide to the Galaxy .
Via Wired; see also the Emdrive website.
Scroll down for more stories in the same category. (Story submitted 9/29/2008)
Follow this kind of news @Technovelgy.| Email | RSS | Blog It | Stumble | del.icio.us | Digg | Reddit |
Would
you like to contribute a story tip?
It's easy:
Get the URL of the story, and the related sf author, and add
it here.
Comment/Join discussion ( 5 )
Related News Stories - (" Space Tech ")
SETI Suggests Prospecting The Solar System Without Landing
'From a distance it could resolve the cosmic rays reflected from various substances.' - Philip Nowlan w/D. Calkins, 1929.
Cislunar Space And The Space Lanes of Golden Age Science Fiction
'He had travelled the space-lanes of the solar system for the greater part of his life...' - Edmond Hamilton, 1928.
NASA Moonbase Update
'The dinner was excellent. It was completely vegetarian — grown in specially prepared gardens in this Moon base...' - Jim Vanny, 1931.
The Solar Oberth Slingshot
'And if it doesn’t work,' inquired Lazarus, 'what does that make us? Sunspots?' - Robert Heinlein, 1941.
Technovelgy (that's tech-novel-gee!) is devoted to the creative science inventions and ideas of sf authors. Look for the Invention Category that interests you, the Glossary, the Invention Timeline, or see what's New.
Science Fiction
Timeline
1600-1899
1900-1939
1940's 1950's
1960's 1970's
1980's 1990's
2000's 2010's
Current News
Prairie Madness - And Space Sickness
'Space-sickness is one of the most unpleasant sensations that a human being can experience. Not all are subject to it...'
Can Stratospheric Aerosol Injection Control The Weather?
'...I saw a nice black heavy-looking cloud sailing by just now, and I can get the electrical machine out in five minutes to draw it down.'
SETI Suggests Prospecting The Solar System Without Landing
'From a distance it could resolve the cosmic rays reflected from various substances.'
Wolfram Alpha Mathematica Predicted by Science Fiction in 1948!
'The answer to the dumb student's prayer.'
Cislunar Space And The Space Lanes of Golden Age Science Fiction
'He had travelled the space-lanes of the solar system for the greater part of his life...'
NASA Moonbase Update
'The dinner was excellent. It was completely vegetarian — grown in specially prepared gardens in this Moon base...'
Neuralink Will Allow Humans To Communicate With ... Animals?
'Telepaths had their sensitiveness enlarged to an immense range by the pin-sets, which were telepathic amplifiers adapted to the mammal mind.'
Special Lights For Driverless Cars!
'That light is actually the Anamorphic Equalizer...'
'Old People Began to Cross The Continent In Their Own Cars'
'It was a relief to enter one of the comfortable autos, whisper a direction down the tube, and just know that you would be taken to your destination in the quickest, safest, and cheapest manner.'
Harrison Bergeron, Illustrated And Practiced
'But he didn't get very far with it before another noise in his ear radio scattered his thoughts. George winced...'
Starfall Manufacturing Drugs In Space
'The vast spinning sphere of Factory in the Sky loomed above and ahead of us, gleaming white against the unfathomable jet depths of surrounding space.'
The Solar Oberth Slingshot
'And if it doesn’t work,' inquired Lazarus, 'what does that make us? Sunspots?'
'Maybe The Woman Of Your Life Is Still Under Production'
'The Dillard people had performed a miracle and put all the works in a girl-modeled case.'
'If Anyone Is Watching Earth...'
'Our study of your race has convinced us that you are not fitted to leave your planet in the present state of your civilization.'
Epirus High-Power Microwave Defeats Drones
'...the spreading beam of the deranging ray struck them, and Then one toppled and fell. Then another.'
Cloud Of Space Rubbish From China's Long March Rocket
'Within seconds the material was spread out over fifty yards, in a matter of hours it might occupy several cubic miles of space...'
